Per NFL rules, Hayden cannot practice or play for the regular-season’s first six weeks.

From that point, he has a five-week window to start practicing. Then he’d have 21 days before being activated or placed on season-ending injured reserve.

That’s a huge blow for a player expected to start at cornerback this season. He added strength and speed in the offseason, prolonged by sports hernia surgery halfway though his rookie season.

A breakthrough was expected before Hayden hurt himself early in OTAs. He was originally diagnosed with an ankle injury, but a second MRI revealed a stress fracture in his foot that had to be manually repaired. He had surgery shortly after minicamp in mid-June.

Hayden has been out roughly nine weeks and apparently isn’t close to a return. On Monday, head coach Dennis Allen said Hayden had not suffered a setback in his recovery.

Allen said he saw signs for encouragement from Hayden’s recent side sessions, which included running and cutting on a side field.

Allen said Monday that the Raiders would wait until Saturday, when rosters drop to 53, before making a tough call on Hayden.

“We’re going to push it all the way up until the deadline, until we find out exactly where he is,” head coach Dennis Allen said. “We’ll wait and see what we have to do on that.”

Allen didn’t wait that long. He pulled the trigger less than 24 hours later despite having more time to evaluate Hayden, suggesting that there was little to no chance of Hayden being close enough to avoid the PUP designation.

This is yet another blow in a troubling start to Hayden’s NFL career. The Raiders drafted him No. 12 overall despite suffering a ruptured blood vessel in a Nov. 2012 practice at the University of Houston. He had a related surgery before the 2013 offseason program.

He made just two starts his rookie season and was primarily an outside corner in the nickel package. He only made it through half the year before a sports hernia put him on the shelf.

Even if Hayden comes back at the earliest allowable date, he will have not played a game in over 11 months. Even that may be unrealistic. Defensive coordinator Jason Tarver said last week that Hayden would have to earn his place in the secondary and get re-acclimated through practice reps.